Validity of sheet-type portable monitoring device for screening obstructive sleep apnea syndrome

Piezoelectric rubber sheet sensor: a promising tool for home sleep apnea testing

PURPOSE

This study aimed to develop an unobtrusive method for home sleep apnea testing (HSAT) utilizing micromotion signals obtained by a piezoelectric rubber sheet sensor.

METHODS

Algorithms were designated to extract respiratory and ballistocardiogram components from micromotion signals and to detect respiratory events as the characteristic separation of the fast envelope of the respiration component from the slow envelope. In 78 adults with diagnosed or suspected sleep apnea, micromotion signal was recorded with a piezoelectric rubber sheet sensor placed beneath the bedsheet during polysomnography. In a half of the subjects, the algorithms were optimized to calculate respiratory event index (REI), estimating apnea-hypopnea index (AHI). In the other half of subjects, the performance of REI in classifying sleep apnea severity was evaluated. Additionally, the predictive value of the frequency of cyclic variation in heart rate (Fcv) obtained from the ballistocardiogram was assessed.

RESULTS

In the training group, the optimized REI showed a strong correlation with the AHI (r = 0.93). Using the optimal cutoff of REI ≥ 14/h, subjects with an AHI ≥ 15 were identified with 77.8% sensitivity and 90.5% specificity. When applying this REI to the test group, it correlated closely with the AHI (r = 0.92) and identified subjects with an AHI ≥ 15 with 87.5% sensitivity and 91.3% specificity. While Fcv showed a modest correlation with AHI (r = 0.46 and 0.66 in the training and test groups), it lacked independent predictive power for AHI.

CONCLUSION

The analysis of respiratory component of micromotion using piezoelectric rubber sheet sensors presents a promising approach for HSAT, providing a practical and effective means of estimating sleep apnea severity.

Noninvasive monitoring technologies to identify discomfort and distressing symptoms in persons with limited communication at the end of life: a scoping review

BACKGROUND

Discomfort and distressing symptoms are common at the end of life, while people in this stage are often no longer able to express themselves. Technologies may aid clinicians in detecting and treating these symptoms to improve end-of-life care. This review provides an overview of noninvasive monitoring technologies that may be applied to persons with limited communication at the end of life to identify discomfort.

METHODS

A systematic search was performed in nine databases, and experts were consulted. Manuscripts were included if they were written in English, Dutch, German, French, Japanese or Chinese, if the monitoring technology measured discomfort or distressing symptoms, was noninvasive, could be continuously administered for 4 hours and was potentially applicable for bed-ridden people. The screening was performed by two researchers independently. Information about the technology, its clinimetrics (validity, reliability, sensitivity, specificity, responsiveness), acceptability, and feasibility were extracted.

RESULTS

Of the 3,414 identified manuscripts, 229 met the eligibility criteria. A variety of monitoring technologies were identified, including actigraphy, brain activity monitoring, electrocardiography, electrodermal activity monitoring, surface electromyography, incontinence sensors, multimodal systems, and noncontact monitoring systems. The main indicators of discomfort monitored by these technologies were sleep, level of consciousness, risk of pressure ulcers, urinary incontinence, agitation, and pain. For the end-of-life phase, brain activity monitors could be helpful and acceptable to monitor the level of consciousness during palliative sedation. However, no manuscripts have reported on the clinimetrics, feasibility, and acceptability of the other technologies for the end-of-life phase.

CONCLUSIONS

Noninvasive monitoring technologies are available to measure common symptoms at the end of life. Future research should evaluate the quality of evidence provided by existing studies and investigate the feasibility, acceptability, and usefulness of these technologies in the end-of-life setting. Guidelines for studies on healthcare technologies should be better implemented and further developed.

Portable evaluation of obstructive sleep apnea in adults: A systematic review

Obstructive sleep apnea (OSA) is a significant healthcare burden affecting approximately one billion people worldwide. The prevalence of OSA is rising with the ongoing obesity epidemic, a key risk factor for its development. While in-laboratory polysomnography (PSG) is the gold standard for diagnosing OSA, it has significant drawbacks that prevent widespread use. Portable devices with different levels of monitoring are available to allow remote assessment for OSA. To better inform clinical practice and research, this comprehensive systematic review evaluated diagnostic performances, study cost and patients' experience of different levels of portable sleep studies (type 2, 3, and 4), as well as wearable devices and non-contact systems, in adults. Despite varying study designs and devices used, portable diagnostic tests are found to be sufficient for initial screening of patients at risk of OSA. Future studies are needed to evaluate cost effectiveness with the incorporation of portable diagnostic tests into the diagnostic pathway for OSA, as well as their application in patients with chronic respiratory diseases and other comorbidities that may affect test performance.

Association between sleep quality, hypertensive disorders of pregnancy, and sleep-disordered breathing in pregnant women with and without obesity: An observational cross-sectional study

AIM

To elucidate whether pregnancy and obesity are associated with poor sleep quality, and to investigate if sleep quality is associated with hypertensive disorders of pregnancy in pregnant women with obesity.

METHODS

This observational cross-sectional study examined 15 obese pregnant women (body mass index ≥30 kg/m² ) (p-Ob group), 15 nonobese pregnant women (p-nOb group), and 30 nonobese nonpregnant women (n-Pr group), using home recording devices to monitor sleep-disordered breathing (SDB): respiratory disturbance index, oxygen saturation, and sleep stage and quality. These variables were compared among the groups. Moreover, obese women with and without hypertensive disorders of pregnancy were compared.

RESULTS

Significant differences in respiratory disturbance index (median: 10.3 [p-Ob], 7.1 [p-nOb], 3.5 [n-Pr]) and oxygen saturation (95.1%, 96.5%, and 96.6%) were observed among the groups. Seven participants in the p-Ob group experienced hypertensive disorders of pregnancy with SDB before or after sleep examination. Particularly, those who developed hypertensive disorders of pregnancy before sleep examination showed a lower delta power throughout the night than those without this condition.

CONCLUSION

Pregnant women had poor sleep quality; those with obesity had higher frequency of SDB with worsened respiratory conditions that might cause complications. Our findings suggest that the development of hypertensive disorders of pregnancy in some obese pregnant women might be associated with insufficient delta power. Focusing on delta power may reflect subtle changes in sleep quality that occur in pregnant women. Future longitudinal studies with larger sample sizes are required to confirm these findings and investigate causality.

A Minimum Set of Physiological Parameters to Diagnose Obstructive Sleep Apnea Syndrome Using Non-Invasive Portable Monitors. A Systematic Review

Introduction. Despite its high accuracy, polysomnography (PSG) has several drawbacks for diagnosing obstructive sleep apnea (OSA). Consequently, multiple portable monitors (PMs) have been proposed. Objective. This systematic review aims to investigate the current literature to analyze the sets of physiological parameters captured by a PM to select the minimum number of such physiological signals while maintaining accurate results in OSA detection. Methods. Inclusion and exclusion criteria for the selection of publications were established prior to the search. The evaluation of the publications was made based on one central question and several specific questions. Results. The abilities to detect hypopneas, sleep time, or awakenings were some of the features studied to investigate the full functionality of the PMs to select the most relevant set of physiological signals. Based on the physiological parameters collected (one to six), the PMs were classified into sets according to the level of evidence. The advantages and the disadvantages of each possible set of signals were explained by answering the research questions proposed in the methods. Conclusions. The minimum number of physiological signals detected by PMs for the detection of OSA depends mainly on the purpose and context of the sleep study. The set of three physiological signals showed the best results in the detection of OSA.

Clinical usefulness of the body muscle-to-fat ratio for screening obstructive sleep apnea syndrome in patients with inadequately controlled type 2 diabetes mellitus

AIMS

To investigate whether body composition measures can be used for screening obstructive sleep apnea syndrome (OSAS) in patients with type 2 diabetes mellitus (T2DM) suspected of having OSAS.

METHODS

Subjects were 186 hospital inpatients with inadequately controlled T2DM. We measured the respiratory disturbance index (RDI) as an indicator of OSAS using a sheet-type breath detection monitor, defining OSAS as an RDI ≥ 19 events/hour. Elementary body composition was measured by bioelectrical impedance analysis using InBody770.

RESULTS

Simple logistic regression analysis identified body weight, body mass index (BMI), waist circumference, total body fat mass, body fat percentage, and body muscle-to-fat ratio (BMFR) as significantly associated with OSAS. The Nagelkerke R² test showed that the BMFR was the most suitable measure for screening OSAS. Multivariate logistic regression analysis demonstrated that BMFR was significantly and independently associated with OSAS. In receiver operating characteristic curve analysis, the area under the BMFR curve was 0.70 (P < 0.001), indicating that BMFR was significantly predictive of OSAS. Furthermore, BMFR was the most suitable measure for screening OSAS in a sub-group analysis of non-obese patients with relatively low BMI (<27.5 kg/m²).

CONCLUSIONS

In patients with T2DM, the BMFR is useful for screening OSAS in daily clinical practice.

Devices for home detection of obstructive sleep apnea: A review

One of the most common sleep-related disorders is obstructive sleep apnea, characterized by a reduction of airflow while breathing during sleep and cause significant health problems. This disorder is mainly diagnosed in sleep labs with polysomnography, involving high costs and stress for the patient. To address this situation multiple systems have been proposed to conduct the examination and analysis in the patient's home, using sensors to detect physiological signals that are examined by algorithms. The objective of this research is to review publications that show the performance of different devices for ambulatory diagnosis of sleep apnea. Commercial systems that were examined by an independent research group and validated research projects were selected. In total 117 articles were analysed, including a total of 50 commercial devices. Each article was evaluated according to diagnostic elements, level of automatisation implemented and the deducted level of evidence and quality rating. Each device was categorized using the SCOPER categorization system, including an additional proposed category, and a final comparison was performed to determine the sensors that provided the best results.

Diagnostic accuracy of level IV portable sleep monitors versus polysomnography for obstructive sleep apnea: a systematic review and meta-analysis

PURPOSE

Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder. In-laboratory, overnight type I polysomnography (PSG) is the current "gold standard" for diagnosing OSA. Home sleep apnea testing (HSAT) using portable monitors (PMs) is an alternative testing method offering better comfort and lower costs. We aimed to systematically review the evidence on diagnostic ability of type IV PMs compared to PSG in diagnosing OSA.

METHODS

Participants: patients ≥16 years old with symptoms suggestive of OSA;intervention: type IV PMs (devices with < 2 respiratory channels); comparator: in-laboratory PSG; outcomes: diagnostic accuracy measures;studies: cross-sectional, prospective observational/experimental/quasi-experimental studies; information sources: MEDLINE and Cochrane Library from January 1, 2010 to May 10, 2016. All stages of review were conducted independently by two investigators.

RESULTS

We screened 6054 abstracts and 117 full-text articles to select 24 full-text articles for final review. These 24 studies enrolled a total of 2068 patients with suspected OSA and evaluated 10 different PMs with one to six channels. Only seven (29%) studies tested PMs in the home setting. The mean difference (bias) between PSG-measured and PM-measured apnea-hypopnea index (AHI) ranged from - 14.8 to 10.6 events/h. At AHI ≥ 5 events/h, the sensitivity of type IV PMs ranged from 67.5-100% and specificity ranged from 25 to 100%.

CONCLUSION

While current evidence is not very strong for the stand-alone use of level IV PMs in clinical practice, they can potentially widen access to diagnosis and treatment of OSA. Policy recommendations regarding HSAT use should also consider the health and broader social implications of false positive and false negative diagnoses.

Validation of a novel sleep-monitoring system for diagnosing obstructive sleep apnea: A comparison with polysomnography

Overnight polysomnography (PSG) is currently the gold standard for diagnosing obstructive sleep apnea (OSA); however, it is time-consuming, expensive and uncomfortable for the patient. A micromovement sensitive mattress (MSM) sleep-monitoring system was developed as an alternative to PSG, however, there has yet to be a study verifying the accuracy of diagnosing OSA with this device. Therefore, the present study assessed the validity of the MSM sleep-monitoring system. Chinese Han participants who were suspected of having OSA were recruited between June 2013 and June 2014. The MSM sleep-monitoring system and PSG were utilized simultaneously overnight on each subject. The apnea-hypopnea index (AHI) was measured by the MSM sleep-monitoring system (AHI_MSM) and compared with that determined by PSG (AHI_PSG), revealing a significant correlation between the two values (r=0.97, P<0.001). Bland-Altman plots also indicated good agreement (97%) between MSM and PSG. Using an AHI_PSG cut-off of ≥5, ≥15 and ≥30 events/h, the sensitivity (specificity) of detecting an AHI_MSM of ≥5, ≥15, and ≥30 events/h were 94.9 (100%), 89.9 (96.9%) and 90.3% (94.9%), respectively. The areas under the receiver operating characteristic curve, which were used to differentiate an AHI_PSG of ≥5, ≥15 and ≥30 events/h in clinically diagnosed OSA, were 0.984, 0.982 and 0.980, respectively. Thus, the MSM sleeping system may accurately diagnose OSA in the Chinese Han population. Further community-based studies with larger sample sizes are warranted to confirm the validity of this MSM sleeping system.

Association of sleep-disordered breathing with decreased cognitive function among patients with dementia

Sleep is known to be essential for proper cognitive functioning. Sleep disturbance, especially respiratory disturbance during sleep, is a risk factor for the development of dementia. However, it is not known whether hypopnoea during sleep is related to severity of cognitive function in patients already diagnosed with dementia. Considering the high prevalence of sleep problems in aged people, it is important to determine if hypopnoea during sleep contributes to dementia. In addition, it would be desirable to develop a feasible method for objectively evaluating sleep in patients with dementia. For this purpose, a simple sleep recorder that employs single or dual bioparameter recording, which is defined as a type-4 portable monitor, is suitable. In this study, a type-4 sleep recorder was used to evaluate respiratory function during sleep in 111 patients with dementia, and data suggesting a possible relationship with cognitive function levels were examined. Multivariate logistic regression was used to investigate the association of severity of dementia with sleep-disordered breathing, age, diabetes, dyslipidaemia and hypertension. It was found that the respiratory disturbance index was associated with severity of cognitive dysfunction in our subjects. Furthermore, patients younger than 80 years were more susceptible to lower cognitive function associated with sleep-disordered breathing than patients 80 years old or over, because an increase in the respiratory disturbance index was associated with deteriorated cognitive function only in the former age group. These results suggest that proper treatment of sleep apnea is important for the preservation of cognitive function, especially in patients with early-stage dementia.

The accuracy and uncertainty of a sheet-type portable monitor as a screening device to identify obstructive sleep apnea-hypopnea syndrome

OBJECTIVE

Laboratory-based polysomnography (PSG) is the gold standard for diagnosing obstructive sleep apnea-hypopnea syndrome (OSAHS), but it is expensive and requires overnight hospitalization. Recently, a sheet-shaped breath detection monitor, the SD-101, has been developed, and several reports have so far demonstrated the screening accuracy of this device. The aim of this study was to assess the accuracy and the uncertainty of this device.

METHODS

A total of 101 suspected OSAHS patients underwent simultaneous examinations with PSG and the SD-101.

RESULTS

There was a statistically significant relationship between the respiratory disturbance index (RDI) by the SD-101 and the apnea-hypopnea index (AHI) by PSG. At an RDI cutoff of 14 episodes per hour, the sensitivity and specificity to detect an AHI ≥20 episodes per hour were 90.2% and 90.0%, respectively. To reduce the influence of sleep efficiency, the time in bed (TIB) obtained from PSG, instead of the total seep time (TST), was used to calculate the AHI from the PSG data. There was also a statistically significant relationship between the RDI and AHI for the TIB. Moreover, it was suggested that arousal index and TIB were likely associated with false-negative and/or false-positive results.

CONCLUSION

Although the present study demonstrated a close relationship between the RDI and the AHI, use of the SD-101 to examine symptomatic OSAHS patients should be performed with a full understanding of its incapability to detect the sleep state, including arousal reaction and the existence of false respiratory events caused by body movements.